The invention relates to an apparatus for removing solid particles from the cooling water for power plants and the like. It has a tubular housing and, attached to its interior, a funnel-shaped trap sieve, the pointed end of which extends in the flow direction. A pressurized water sprayer includes a washer arm concentrically rotatable about the downstream side of the sieve. The arm has at least one discharge nozzle facing the downstream side of the sieve. Further, a suction tube extends into a collecting chamber of the sieve.
Large quantities of water are required to cool heat exchangers in steam-operated and other types of power plants. The cooling water must be cleaned regularly to prevent solid particles therein, such as wood, plastic, leaves, blades of grass, shells and the like from clogging and damaging parts of the plant. The larger particles are removed by means of rakes. However, the finer particles are typically removed with trap sieves by suctioning them off the upstream side of the sieve. To dislodge and remove particles which adhere to and clog trap sieve perforations, the prior art employs suction arms as is disclosed, for a cylindrical trap sieve, in U.S. Pat. No. 2,275,958, and for a funnel-shaped sieve, in German Utility Model No. DE-GM 83 37 300. Such arms have suction slots which rotate proximate the upstream side of the trap sieve. These constructions have proven disadvantageous because larger particles, e.g. wood, shells, etc. frequently jam the suction arm as it rotates about the upstream side of the trap sieve, thus rendering the arm, or the arm together with the trap sieve inoperable. This distinct disadvantage is also encountered with a commercially well-known apparatus, which has, in addition to a suction arm rotatable about the upstream side, a washer arm at the downstream side of the sieve positioned opposite the suction arm and rotating therewith. In this construction pressurized water is sprayed through nozzle slits against the downstream side of the sieve to clean the sieve perforations. Moreover, a construction incorporating both a suction arm rotating about the upstream side of the sieve and a washer arm rotating about the downstream side is very costly.